1. Field of the Invention
The present invention relates to a display control apparatus which switches displayed images while scrolling them, and a method of controlling the same.
2. Description of the Related Art
An image reproduction apparatus such as a digital camera is conventionally equipped with a scroll image switching effect to switch from a currently displayed image to the next or previous image by scroll operations in the horizontal or vertical direction upon, for example, reproduction display of representative images of still images or moving images. Additionally, with the advent of user interfaces using a touch panel, a screen switching method for scrolling in accordance with the operation of a finger placed on the screen is becoming popular.
Japanese Patent Laid-Open No. 05-100809 discloses scrolling displayed objects in the moving direction of the finger by setting the finger moving speed as the initial velocity upon determining that the moving amount or moving speed of the finger on the touch panel has exceeded a predetermined value. This document also discloses after the user has moved the finger off the panel, decelerating and stopping the scroll.
Japanese Patent Laid-Open No. 2002-125190 discloses making the image fast-forward instruction key compatible with analog input and changing the fast-forward speed based on the input value. The larger the depression force on the key or the key tilt angle is, the higher the fast-forward speed is. As the fast-forward speed increases, the display size per image to be smooth-scrolled decreases.
On the other hand, if the aspect ratio of an image does not match that of the display area, the image is displayed while making its size coincide with the display area size in one direction. Black bars are displayed horizontally above and below the image (letterbox) or vertically on both sides of the image (pillarbox).
Japanese Patent Laid-Open No. 2007-096472 discloses displaying a black image on the left and right sides of a 16:9 wide liquid crystal display, thereby displaying a 4:3 image.
However, when feeding images at a higher scroll speed by simply increasing the operation speed of single image feed, the following problems arise. That is, especially when scrolling images such as still images in different aspect ratios, non-image areas (in general, pillar box display portions such as black image areas) inserted in the scroll direction need to be scrolled as well. For this reason, even if the user wants to quickly display the next image by speeding up the scroll, scrolling the non-image areas takes time. In addition, if the image size is decreased to speed up image feed, as Japanese Patent Laid-Open No. 2002-125190, or the scroll speed is too high, the viewability of scrolled images lowers.